The Ontario Building Code | Extension, Material Alteration or Repair
11.3.4.1. Extension, Material Alteration or Repair
(1) Despite Subsections 11.3.1. to 11.3.3., when an existing building is extended or subject to material alteration or repair, Part 7 applies,
(a) to the design and construction of plumbing in the extensions and those parts of the buildingsubject to material alteration and repair, and
(b) to plumbingwhich is adversely affected by the extension, alteration or repair.
11.3.5. Sewage Systems